are these surveys carol is pointing out do, they impress you? >> not really. we're not really seeing the actual data. she talks about 4 x dollar ad spend, 5x, and i think people are suitably skeptical of those numbers and not that facebook can't be a profitable place to advertise, but 60 studies seems like over kill. the proof will be in the pudding when the advertisers themselves put more revenue in the facebook platform and we get to mobile and i think the main thing right now and jason probably has this problem is more data on mobile, as much as possible, because if we know overall how much on the secular basis it is moving to mobile, that in effect becomes the business. >> i think the big issue is not just how users are shifting but where advertisers are putting dollars and e-market projects that mobile ad revenue will grow 80% this year and i think the big question is how much of that growth can facebook get a piece of? >> right. >> go on. >> i think if you look at desk top usage, this is a statistic and in the month of august 12 to 17-year-olds were down